Static electricity can be a problem for resin casting with both resin and silicone. Typically it’s not much of an issue with silicone for mold making as larger amounts are being poured in. Some silicone being strung out of place is usually ok as it is fairly easy to clean up once it’s cured. The same cannot really be said for resin, specially for multi shot casts where small details are being added to your molds.
Often times toothpicks are suggested for adding small resin details to your mold since they have a fairly narrow tip and are small enough to get into tight areas. However in my experience with using toothpicks, the static electricity seems to be more prevalent. Many times I will dip the tip of a toothpick into some resin and while bringing it close to my mold, the static electricity will pull the resin off the toothpick and shoot stringers off into several directions, spreading thin hairlines of resin all over the mold. This is pretty frustrating when it happens a lot and one has to constantly try to clear out those stringers after the resin has cured. I would use fine tip tweezers and tape in order to grab it out, but never really being able to get it all.
After a friend suggested using blunt tip syringes for making fine details into clay and also for squirting small amounts of resin into tighter pockets of a mold. I noticed that the static electricity wasn’t giving me any issues anymore. After several uses of blunt tip syringes, I have not had a single problem with static electricity. Not only are they excellent for adding small details of resin to molds, but they also come in various sizes, many of which are much finer than the tip of a toothpick. So these are my go to tools for adding small details.

This is not a full proof method for guaranteeing there will be no static electricity but it’s definitely a lot better than toothpicks. I have noticed that new silicone molds will experience static electricity more often. Usually after the first time use with resin in them and under a bit of heat, it usually removes the static electricity.

One thing to note is that the smaller blunt tip syringes will not be able to suck up or eject resin as they are so fine and the resin is just too thick. So I keep a separate set of different tip sized just for applying drips or small dabs of resin into molds and don’t worry about the tips clogging as they will only be used for this purpose. And then I keep other tips for injecting resin and as soon as I am finished using them, I rinse them out in acetone, swishing them back and forth multiple times to properly clean them out to be useable for the next time.

These are readily available on